ANKARA: Turkish Prime Minister Recep Tayyip Erdogan said Wednesday he was ready to step down if his ruling party, in power since 2002, loses key local elections later this month.

“I am ready to quit politics unless my party emerges winner in the elections” scheduled for March 30, said Erdogan, who is battling a damaging corruption investigation which poses the greatest challenge yet to his 11 years in power.

But the opposition slammed Erdogan's remarks as a “show of defiance”.

“It is equal to taking hostage the will of the people and disrespecting society. Are the people obliged to vote for Erdogan?” asked Mehmet Sandir, the deputy head of the Nationalist Movement Party (MHP).

The graft scandal broke in December with the detention of dozens of Erdogan allies on allegations of bribery, money laundering, gold smuggling and illicit dealings with Iran.

Erdogan has accused associates of ally-turned-opponent Fethullah Gulen, an influential Muslim cleric based in the United States, of concocting the probe.

But the scandal, and his hardline response to it, have done unprecedented damage to the premier's image at home and abroad.

Opinion polls show the scandal is hurting Erdogan's Justice and Development Party (AKP), which weathered mass street protests in mid-2013.

A January survey by the Metropoll research company showed support for the AKP at 36.3 per cent, far below the 50 per cent it garnered in 2011's parliamentary elections.

Audio tapes

The Turkish strongman remained defiant, saying Wednesday the number of supporters filling election rallies suggested a backlash in his favour.

But Erdogan has come under increased pressure since last week, when audio tapes leaked online put him at the heart of the corruption allegations.

The recordings were purportedly of Erdogan and his son Bilal discussing how to hide large sums of money.

Erdogan on Wednesday for the first time confirmed the authenticity of a leaked tape of him and former justice minister Sadullah Ergin after denouncing the previous recordings as “fakes”.

In the recording published on Monday, Erdogan tells Ergin to keep tabs on a court case to make sure a media mogul, who has been at odds with the premier, is convicted.

In a new tape revealed on Wednesday, Erdogan is allegedly heard intervening in the election of candidates to the council of state's presidency, seen as another bid to control the judiciary.

The tapes prompted opposition calls for the beleaguered government's resignation.

And thousands of people have taken to the streets across the country in protest, with police on occasion firing tear gas and rubber bullets to disperse the demonstrators.

The embattled premier has responded by sacking or reassigning hundreds of police and prosecutors believed to be linked to the Gulen movement, and tightened his grip on the Internet and the judiciary.

Gulen himself denies any involvement in launching the scandal.

In the latest blow to the Gulenists, the Turkish parliament, where Erdogan's AKP has a comfortable majority, passed a law on Friday to shut down a network of private preparatory schools most of which are run by the movement.

In remarks published in local media Wednesday, Erdogan vowed to take action against the Gulen group after the elections. “We will promptly take several measures after the March 30 local elections,” he said, without elaborating.

At its February meeting, Turkey's National Security Council discussed “organisations and structures” that threaten the country's national security interests.